- Click here for explanation of classification scheme.

To characterize the separate and combined effects of HIV infection and alcoholism on motor functions, the authors examined upper and lower limb motor abilities in patients with HIV infection and alcoholism alone and those comorbid for both conditions using a variety of tasks known to be differentially sensitive to frontostriatal or frontocerebellar dysfunction.

• None listed
• Readers are referred to Rosenbloom et al, 2007 reference for a more detailed description of subject inclusion or exclusion criteria.

• Significant history of psychiatric or neurological disorder not related to their primary diagnosis
• History of past or present alcohol or drug abuse or dependence in the NC group
• Recent (within the last three months) substance dependence other than alcohol in the patient groups
• Serious medical condition
• HIV-related opportunistic infection
• CD4 less than 100 cells/mm³ at initial visit
• Karnofsky score less than 70
• Readers are referred to the Rosenbloom et al, 2007 reference for a more detailed description of subject inclusion and exclusion criteria.

Recruitment

• Subjects were recruited from HIV clinics and local substance abuse treatment programs
• Controls were volunteers recruited from the local community. 

Design

Case-Control Study 

Blinding used (if applicable)

Implied for laboratory measures

Intervention (if applicable)

Comparison groups were:

• HIV-infected
• Alcoholic
• HIV-infected with alcoholism
• Control (NC).

Statistical Analysis

• Test scores were age corrected based on the scores of the control group (Z score mean and SD for each measure equals zero ± for control group) to examine group effect size, compare performance using standardized scores across measures, and assess whether comorbidity of HIV infection and alcoholism resulted in greater motor deficits compared with the single diagnosis groups
• Z scores were not computed for the Walk Heel-to-Toe task with eyes open because the control group performed perfectly without variance
• Three composite scores were calculated, (1) upper motor, (2) lower motor: Open eyes, and (3) lower motor: Closed eyes, by averaging age-corrected Z scores within each domain. Specifically, the upper motor composite score consisted of the average age-corrected Z score obtained on fine finger movement, finger tapping, grooved pegboard, RT, and MT. The lower motor: Open eyes composite score consisted of the average Z score obtained on the Stand Heel-to-Toe and Stand on One Leg with eyes open tasks. The lower motor: Closed eyes composite score was calculated by averaging the Z score of the Stand Heel-to-Toe, Walk Heel-to-Toe, and Stand on One Leg with eyes closed tasks.
• The authors tested group differences with parametric analyses (analyses of variance for three- and four-group analyses; T-tests for two-group analyses). Non-parametric analyses were used when subject groups were small (N<15) and for confirmatory analyses to guard against outliers.
• Pearson's correlations were used to test relationships between motor scores and other variables (e.g., demographic and medical indices)
• Alpha level was set at P=0.05 for group comparisons, and a family-wise Bonferroni's correction was instituted for multiple correlational analyses (P ≤0.017 for three comparisons and P ≤0.025 for two comparisons). 

Timing of Measurements

Not listed; one time measurement of outcomes

Dependent Variables

• Semi-structured interview to quantify lifetime alcohol consumption and periods of heavy drinking (more than 12 drinks per day)
• HIV status: Blood samples for HIV Ab, plasma viral load and CD4 cell count
• Premorbid IQ score: Peabody Picture Vocabulary Test, PPVT-III.

Neuropsychological measures

• Upper Limb Motor Measures: Required speeded movement and chosen for sensitivity to frontostriatal integrity; Fine Finger Movement Test; Finger Tapping Test; Grooved Pegboard Test; Two-Choice Task
• Lower Limb Motor Measures: Assessed balance and gait; Walk-a-Line Ataxia Battery performed first with eyes open and then eyes closed and consisted of Stand Heel-to-Toe, Walk Heel-to-Toe, Stand on One Leg. Each condition was tested twice, unless a perfect score was achieved on the initial trial, in which case the subject received full credit on that condition.

Independent Variables

• HIV infected
• Alcoholic
• HIV infected with alcoholism
• Control (NC).

Control Variables

 Age, formal education

Initial N

123 men

Attrition (final N)

123 men

Age

• Ranged from 19 to 71; mean ages among groups ranged from 39.1 to 44.9 and was not different among groups (P=0.063)
• Post-hoc analyses to evaluate trend: HIV and ALC greater than HIV, NC.

Ethnicity

Not given

Other relevant demographics

• Education: Ranged from six to 19 years; mean years of education ranged from 13.3 to 15.0 and was not different among groups (P=0.059). Post-hoc analyses to evaluate trend: NC greater than ALC, HIV and ALC.
• Peabody Picture Vocabulary Test - Standard Score: Ranged from 66 to 139; mean scored ranged from 96.0 to 106.0 and was not different among groups (P=0.062). Post-hoc analyses to evaluate trend: NC greater than HIV and ALC.
• Lifetime alcohol consumption (kg): Ranged from zero to 3,656; mean consumption among groups was different (P=0.0001) and was HIV 61.5 (54.7 SD); ALC 971.7 (771.8); HIV and ALC 905.9 (696.7); NC 68.7 (92.7).
• Beck Depression Inventory-II: Ranged from zero to 37; mean score among groups was different (P=0.0002) and was HIV 10.0 (8.3); ALC 11.0 (10.8); HIV and ALC 12.1 (8.2); NC1.8 (2.4).
• CD4 count: Ranged from 128 to 1,389 in HIV groups; mean counts were different between the two groups; HIV 528.9 (252.1); HIV and ALC 449.8 (258.7).

Anthropometrics

None given

Location

California

 All results were presented in Figure format; below are results listed in the text.

• Groups differed on upper motor composite scores [F(3,119)=3.83, P=0.012]. All three clinical groups achieved significantly lower scores than the controls. The patient groups did not differ significantly from one another.
• For the individual measures, post-hoc analyses indicated a group difference in fine finger movement [F(3,1180=4.83, P=0.004], with the HIV [t(51) =2.20, P=0.033] and HIV and ALC [t(62)=3.89, P=0.003] groups slower than controls.
• Statistical trends indicated that the HIV and ALC group was modestly more impaired than either single diagnosis group
• Groups differed significantly on the lower motor: Closed eyes composite score [F(3,1550=3.81, P=0.013] and showed a trend on the lower motor: Open eyes composite (P=0.073). Patient groups did not differ significantly from one another on any lower limb motor score.
• Post-hoc analyses on the lower motor: Open eyes composite score were impaired compared with controls
• All three patient groups were impaired compared with the NC group on the closed eyes composite [HIV vs. NC t(50)=2.94, P=0.005; ALC vs. NC t(46)=3.13, P=0.004; HIV and ALC vs. NC t(61)=2.03, P=0.047].
• Peripheral Neuropathy: In the HIV groups, five of 31 HIV (16%) and 15 of 43 HIV and ALC (35%) subjects reported peripheral neuropathy. HIV-infected individuals with vs. those without neuropathy did not score significantly differently on any motor composite score. Data were reanalyzed to exclude individuals with self-reported neuropathy symptoms and found that the upper limb composite and lower limb composite scores remained significantly different.
• Differences on motor composite scores were not observed between HIV individuals (whether or not comorbid for alcoholism) taking (N=30) and those not taking (N=44) HAART medication
• Motor impairment was not related to AIDS-defining events or CD4 count less than 200, which occurred in 20 of the 71 HIV patients
• CD4 count did not significantly correlate with motor scores
• Examination of subjects prescribed efavirenz showed that those on this medication performed better on the lower limb: Closed eyes composite score than those not taking this medication (Z=2.19, P=0.029). The efavirenz group was better on Standing Heel-to-Toe with eyes closed (Z=2.64, P=0.009) compared with the non-efavirenz group.
• In the two alcoholism groups, neither total lifetime alcohol consumption nor time since last heavy drinking (at least 12 drinks per day) was significantly correlated with any motor composite score
• Current and recent drug abuse or dependence was an exclusionary criterion; however, many of the subjects in the patient groups met lifetime criteria for drug abuse or dependence (35.5% of HIV, 66.7% of ALC, and 81.4% of HIV and ALC subjects met criteria for drug abuse or dependence sometime in their lifetime. Groups did not differ on weeks since last drug diagnosis. Subjects with lifetime drug diagnosis were not more impaired than subjects without lifetime drug diagnosis within the patient groups, as assessed with the motor composite scores. Weeks since last drug diagnosis was not correlated significantly with any of the motor composite scores.

 

 

• Overall, these results demonstrate that HIV infection and alcoholism each exerts separate affects on upper and lower limb motor functions, but that only upper motor abilities involving speeded finger movements are compounded when the disorders co-occur.
• The impairment patterns further suggest that alcoholism comorbidity in persons with HIV infection may explain the presence of exacerbated impairment in speeded finger movement and emphasize the importance of considering alcohol use disorders as a contributing factor in deficits observed in HIV-infected individuals.

Government:

NIAAA

• Readers are referred to the reference of Rosenbloom et al, (2007) for detailed inclusion and exclusion criteria. This seems to be important information that should also be restated in this article.
• No indication of anthropometrics and weight categories of the subjects which to this reviewer is a limitation for this type of study
• Statistics seem unclear in places. For example under Upper Motor Limb, "The patient groups did not differ significantly from one another." But then post-hoc analyses for individual measures are given amongst the patient groups. There is also the perception of strong emphasis on results with statistical trends.
• Author stated limitation: Determination of peripheral neuropathy was made only in the HIV groups and was based on self-report.